Eyes on the new sub-variant of Omicron BA.2.75, identified in India but also intercepted in other countries such as New Zealand and the United Kingdom. “Probable second generation variant, apparent rapid growth and wide geographical spread.” These are some of the characteristics that according to Tom Peacock, virologist at the Department of Infectious Diseases at Imperial College London, should push those involved in surveillance on covid to keep an eye on the new entry in the international panorama of Omicron’s sub-variants: BA.2.75.
Compared to its ‘big sister’ Omicron 2 (BA.2), the new sub-variant “has 8 additional mutations” on the Spike protein, explains Ulrich Elling, a molecular biologist at the Institute of Molecular Biotechnology (Imba) in Vienna. A number considered significant by the experts compared to that observed in other sub-variants (for example in BA.5 they are 3). In all, however, according to the data that are being released via Twitter in these hours, there are 11 mutations that distinguish it from Omicron 5, the current most widespread variant.
And to summarize the main fear that pushes the ‘experts’ to raise the level of attention on this mutant reported mainly from India, where it appears “in rapid growth”, but also intercepted in other countries such as New Zealand and the United Kingdom, is Eric Topol, American scientist director of the Scripps Research Translational Institute in La Jolla, California: the mutations observed on BA.2.75 “could make the immune leak worse than what we are seeing now,” he reflects. This new sub-variant, adds the expert via Twitter, appears in competition with Omicron 5 in India.
The concern is that the lead over BA.5 is significant to the point of making this version of Sars-CoV-2 increasingly contagious, at levels that could be higher than a ‘transmissibility champion’ such as measles.
So much so that Giorgio Gilestro, neurobiologist and lecturer at Imperial College London, says: “If the data on this new BA.2.75 variant were confirmed, then we could also find ourselves facing a Covid-22”.
Elling wonders if it’s “a new lineage to worry about”. The reason? “I don’t like observed mutations – he writes – Before we’re done with the wave of BA.5”, Omicron 5, “we may already have to prepare for the next one”. The eyes are focused in particular on India, the country from which the largest number of BA.2.75 sequences arrives at the moment. Even if the cases linked to this sub-variant are still few, “the international distribution” of the viral sequences communicated to the databases “excludes sequencing errors and makes it highly probable that the real numbers are much higher”, Elling remarks.
“Mutations” observed in BA.2.75 “are also” affecting “the N-terminal domain” and the “receptor binding domain”. But, Elling points out, “it really is too early” to know whether BA.2.75 will have the ability to steal the show from Omicron 2 and Omicron 5. Some mutations (3 for Elling) can make a huge difference. And “the total of 11 distinct mutations between Omicron 5 and BA.2.75 could allow for yet another wave, as BA.5’s immunity may not” be enough to make an adequate wall. For his part, the virologist Peacock does not lose his balance and leaves open another scenario: “It is worth saying that it is also entirely possible that” this new sub-variant “is only growing against the background of BA.2 and that it hits the barrier of BA. .5 and crash. We’ll see. ”